Bacillus thuringiensis subsp. israelensis (Bti) is a biological
larvicide and widely used to control mosquitoes and black flies
[10,11]. Bti showed a fast killing effect with a good toxicology
profile with the absence of cross-resistance with conventionally
used pesticides [12]. Product with Bti causes no harm and is safe
to the bird, man, fish and mammals [13,14]. The mode of action of
endotoxin to kill larvae is still unclear but the sequence of toxin
activation is well studied [15]. Once the bacteria are ingested, the
crystal will be dissolved in the naturally alkaline pH in the larval
midgut and the endotoxin attached were activated. The larvae
usually die within 2 or 3 days [